An ACDelco GM Original Equipment Ignition Knock (Detonation) Sensor monitors the engine for pinging or spark knock, and is a GM-recommended replacement for your vehicle?s original component. The sensor creates a voltage signal based on the vibrations caused by erratic air/fuel mixture combustion; the engine control module uses this signal to adjust the ignition timing and air/fuel mixture. This original equipment ignition knock sensor has been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors. GMrecommended replacement part for your GM vehicles original factory component Offering the quality, reliability, and durability of GM OE Manufactured to GM OE specification for fit, form, and function